This week, our team was introduced to the newest and most important member of our design team, Mortimer, the inflatable test dummy.

Our project’s goal is to design a swim support for a local boy with cerebral palsy and a tracheal tube, a continuation of my Spring ENGI 120 project. During that time, we found that, for safety reasons, it was not feasible to use the user for all of the device testing, but it was also incredibly difficult for us to accurately simulate his lack of muscle of control. We found that in our simulations, our device worked perfectly, but with our user, it was dangerous and failed major design criteria blocks.

So, this time around, we ordered a plastic dummy off of Amazon, picked a name via an online random name generator, and spent a good chunk of our week at the pool, trying to simulate our client using Mortimer, air, water, weights, and other methods. We took the old device with us, since we know how the user reacts when placed in that swim support. It took a long time to get the proper mix to create a slumped forward, almost boneless motion that our user frequently exhibits, and we did some research and decided to fill a lifejacket with a lot of weights in order to simulate our user’s weight.

After two exhausting and extensive rounds of Pugh Scoring, we picked a final design! We drew up a quick prototype of pool noodles, duct tape, mesh, and PVC, as seen below:

Then launched in researching and ordering materials. Our final design consists of an inner tube with backrest, modified with straps to provide extra support and a special mesh seat with extra support underneath the knees and to submerge our user’s body lower into the water, as requested. We then spent a lot of time researching different configurations and materials for straps, in order to provide support for our user, while still being comfortable and easy to use. We ended making small, medium-fidelity belts, then testing them ourselves to settle on a final design.

Next week, I’m looking forward to continuing our prototyping and I’m sure Mortimer is looking forward to doing his job and testing those prototypes!